IJAR.2025.206
Type of Article: Original Research
Volume 13; Issue 3 (September 2025)
Page No.: 9314-9325
DOI: https://dx.doi.org/10.16965/ijar.2025.206
Mast Cell Characterization and Density in Normal and Abnormally Invasive Placental Tissue Using Five Histochemical Stains
Thaer Bahjat ¹ʼ² *, Malak AL-Yawer ¹, Haydar Al- Shamaa ³ʼ⁴.
¹ Department of Anatomy, College of Medicine, University of Baghdad, Baghdad, Iraq.
² College of Pharmacy, Department of Medical & Health Sciences, American University of Iraq Sulaimani, Sulaymaniyah, Iraq.
³ Department of Obstetrics & Gynecology, College of Medicine, University of Baghdad, Baghdad, Iraq.
⁴ Medical City, Baghdad Teaching Hospital, Department of Obstetrics & Gynecology, Baghdad, Iraq.
Corresponding Author: Dr. Thaer Bahjat, American University of Iraq Sulaimani (AUIS), H9C2+WVP, Sulaimani – Kirkuk Rd, Sulaymaniyah, Sulaymaniyah Governorate, 46001. Iraq.
E-Mail: thaer.bahjat@auis.edu.krd
ABSTRACT
Mast cells (MCs) are multifunctional immune cells implicated in tissue remodeling and immune regulation. Yet, their densities and distribution in human placental tissues, particularly in cases of abnormal placental invasion such as placenta accreta spectrum (PAS), remain underexplored. While immunohistochemistry is considered the gold standard for MCs identification, it is resource-intensive, requiring specialized skills, making histochemical staining a practical alternative. Limited studies have provided conflicting results on the most effective histochemical stains for identifying MCs in human placental tissues.
This study aimed to evaluate mast cell density and characterize their histochemical staining properties in placental tissues from control and experimental groups. The control group comprised five normal full-term placentas obtained from vaginal deliveries, while the experimental group included five placentas from cases of placenta accreta spectrum (PAS) delivered by abdominal hysterectomy. Additionally, the study sought to identify the most effective histochemical stain for mast cell identification and characterization
Five histochemical stains; Toluidine Blue, Periodic Acid-Schiff, Giemsa, Hematoxylin & Eosin (H&E), and Alcian Blue with Safranin O were used to stain sections from each placental sample of the control and the experimental groups. MCs were counted in 10 fields at ×400 magnification for each section, and their densities were compared between the control and the PAS cases for all stains used. Statistical significance was set at p = 0.05.
Toluidine Blue enabled the highest mast cell counts, outperforming other stains in identifying and characterizing mast cells. Morphologically, three types of mast cells were recognized according to their granular content. Mast cell densities were significantly higher in placenta accreta cases compared to the control, suggesting a potential role for MCs in the pathogenesis of PAS.
In conclusion, this study highlights the value of histochemical staining—particularly Toluidine Blue—in reliably identifying mast cells within placental tissue. The findings suggest a possible involvement of mast cells in the pathogenesis of placenta accreta, warranting further research into their underlying mechanisms and their potential utility as diagnostic markers or therapeutic targets
Keywords: Mast cells, Placenta Accreta Spectrum, Histochemical staining, Toluidine Blue.
REFERENCES
[1]. American College of Obstetricians and Gynecologists, Cahill, A. G., Beigi, R., Heine, R. P., Silver, R. M., & Wax, J. R. Placenta accreta spectrum. American journal of obstetrics and gynecology, 2018;219(6):B2-B16.
https://doi.org/10.1016/j.ajog.2018.09.042
PMid:30471891
[2]. Xiyao Liua, Wang, Y., Wu, Y., Zeng, J., Yuan, X., Tong, C., & Qi, H. What we know about placenta accreta spectrum (PAS). European Journal of Obstetrics & Gynecology and Reproductive Biology, 2021;259:81-89.
https://doi.org/10.1016/j.ejogrb.2021.02.001
PMid:33601317
[3]. Jauniaux, E., Collins, S., & Burton, G. J. Placenta accreta spectrum: pathophysiology and evidence-based anatomy for prenatal ultrasound imaging. American journal of obstetrics and gynecology, 2018;218(1):75-87.
https://doi.org/10.1016/j.ajog.2017.05.067
PMid:28599899
[4]. Tantbirojn P., Crum C. P., and Parast M. M. Pathophysiology of placenta creta: the role of decidua and extravillous trophoblast. Placenta, 2008;29(7):639-645.
https://doi.org/10.1016/j.placenta.2008.04.008
PMid:18514815
[5]. Church, M. K., & Levi-Schaffer, F. The human mast cell. Journal of Allergy and Clinical Immunology, 1997;99(2):155-160.
https://doi.org/10.1016/S0091-6749(97)70089-7
PMid:9042038
[6]. Galli, S. J., & Tsai, M. Mast cells in allergy and infection: versatile effector and regulatory cells in innate and adaptive immunity. European. journal of immunology, 2010;40(7):1843-1851.
https://doi.org/10.1002/eji.201040559
PMid:20583030 PMCid:PMC3581154
[7]. Féger, F., Varadaradjalou, S., Gao, Z., Abraham, S. N., & Arock, M. The role of mast cells in host defense and their subversion by bacterial pathogens. Trends in immunology 2002;23(3):151-158.
https://doi.org/10.1016/S1471-4906(01)02156-1
PMid:11864844
[8]. Rodini, C.O., Batista, A.L., Lara, V.S., Paolo, S. Comparative immunohistochemical study of mast cells in apical granulomas and periapical cysts. Oral Surg. Oral Med. Oral Path. Oral Radiol. Endod., 2004;97:59-63.
https://doi.org/10.1016/S1079-2104(03)00378-0
PMid:14716257
[9]. Valent P. et al., S. J. Mast cells as a unique hematopoietic lineage and cell system: from Paul Ehrlich’s visions to precision medicine concepts. Theranostics, 2020;10(23):10743.
https://doi.org/10.7150/thno.46719
PMid:32929378 PMCid:PMC7482799
[10]. Iwaki, S., Tkaczyk, C., Metcalfe, D.D., Gilfillan, A.M. Roles of adaptor molecules in mast cell activation. Chem. Immunol. Allergy, 2005;87:43-58.
https://doi.org/10.1159/000087570
PMid:16107762
[11]. Mukai, K., Tsai, M., Saito, H., & Galli, S. J. Mast cells as sources of cytokines, chemokines, and growth factors. Immunological reviews, 2018;282(1):121-150.
https://doi.org/10.1111/imr.12634
PMid:29431212 PMCid:PMC5813811
[12]. Borriello, F., Iannone, R., & Marone, G. Histamine release from mast cells and basophils. Histamine and histamine receptors in health and disease, 2017;121-139.
https://doi.org/10.1007/164_2017_18
PMid:28332048
[13]. Wernersson, S., & Pejler, G. Mast cell secretory granules: armed for battle. Nature Reviews Immunology, 2014;14(7):478-494.
https://doi.org/10.1038/nri3690
PMid:24903914
[14]. Humphries, D. E., Wong, G. W., Friend, D. S., Gurish, M. F., Qiu, W. T., Huang, C., … & Stevens, R. L. Heparin is essential for the storage of specific granule proteases in mast cells. Nature, 1999;400(6746):769-772.
https://doi.org/10.1038/23481
PMid:10466726
[15]. Prydz, K., & Dalen, K. T. Synthesis and sorting of proteoglycans. Journal of cell science, 2000;113(2):193-205.
https://doi.org/10.1242/jcs.113.2.193
PMid:10633071
[16]. Shukla, S. A., Veerappan, R., Whittimore, J. S., Miller, L. E., & Youngberg, G. A. Mast cell ultrastructure and staining in tissue. Mast Cells: Methods and Protocols, 2005;63-76.
[17]. Díaz-Flores L et al. Human mast cells in normal and pathological tissues: morphological and functional aspects. Histol Histopathol. 2005;20(2):507-520.
[18]. Bancroft, J. D., & Gamble, M. (7 Ed.). (2013). Theory and practice of histological techniques. Elsevier health sciences.
[19]. Leclere M., Desnoyers M., Beauchamp G., Lavoie J.P. Comparison of four staining methods for detection of mast cells in equine bronchoalveolar lavage fluid. J Vet Intern ed. 2006;20(2):377-381.
https://doi.org/10.1111/j.1939-1676.2006.tb02871.x
[20]. McManus, J. F. A., in General Cytochemical Methods, edit. by Danielli, J. F., 171 (Academic Press, New York, 1961).
https://doi.org/10.1016/B978-0-12-395584-5.50010-X
[21]. Enerbäck, L. Mast cells in rat gastrointestinal mucosa: I. Effects of fixation. Acta Pathol Microbiol Scand, 1966a;66(3):289-302.
https://doi.org/10.1111/apm.1966.66.3.289
PMid:4162017
[22]. Enerbäck, L. Mast cells in rat gastrointestinal mucosa: 2. Dye‐Binding and Metachromatic Properties. Acta pathologica microbiologica scandinavica, 1966b;66(3): 303-312.
https://doi.org/10.1111/apm.1966.66.3.303
PMid:4162018
[23]. Romeis B. Mikroskopische technik. Spektrum Akademischer Verlag, Heidelberg. 2010.
[24]. Sharma, R., & Saxena, S. Comparative study of the presence of mast cells in periapical granulomas and periapical cysts by toluidine blue and astra blue: possible role of mast cells in the course of human periapical lesions. International Journal of Oral-Medical Sciences, 2010;9(1):17-25.
https://doi.org/10.5466/ijoms.9.17
[25]. Crivellato E, Beltrami CA, Mallardi F, Ribatti D. Paul Ehrlich’s doctoral thesis: a milestone in the study of mast cells. Br. J. Haematol. 2003;123:19-21.
https://doi.org/10.1046/j.1365-2141.2003.04573.x
PMid:14510938
[26]. Broome, H. E., & Villarreal, D. Mast cell detection by histochemical stains and immunohistochemistry in bone marrow biopsies.Archives of Pathology & Laboratory Medicine, 2013;136(7):784-790.
[27]. Patel, R. M., & Shah, M. B. Qualitative and quantitative analysis of mast cells in oral submucous fibrosis using toluidine blue stain and immunohistochemistry. Journal of Oral and Maxillofacial Pathology, 2009;13(1):8-12.
[28]. Irani AM, Schwartz LB: Mast cell heterogeneity. Clin Exp Allergy 1989;19:143-155.
https://doi.org/10.1111/j.1365-2222.1989.tb02357.x
PMid:2473830
[29]. Huntley JF. Mast cells and basophils: histochemical and immunological techniques. Histochem J. 1995;27(4):341-356.
[30]. Al Drees, A., Khalil, M. S., & Soliman, M. Histological and immunohistochemical basis of the effect of aminoguanidine on renal changes associated with hemorrhagic shock in a rat model. Acta Histochemica et Cytochemica, 2017;50(1):11-19.
https://doi.org/10.1267/ahc.16025
PMid:28386146 PMCid:PMC5374099
[31]. Greene, J., Louis, J., Korostynska, O., & Mason, A. State-of-the-art methods for skeletal muscle glycogen analysis in athletes-the need for novel non-invasive techniques. Biosensors, 2017;7(1):11.
https://doi.org/10.3390/bios7010011
PMid:28241495 PMCid:PMC5371784
[32]. Rabelo, K., de Souza Campos Fernandes, R. C., Souza, L. J. D., Louvain de Souza, T., Santos, F. B. D., Guerra Nunes, P. C., … & Paes, M. V. Placental histopathology and clinical presentation of severe congenital Zika syndrome in a human immunodeficiency virus-exposed uninfected infant. Frontiers in Immunology, 2017;8: 1704.
https://doi.org/10.3389/fimmu.2017.01704
PMid:29270171 PMCid:PMC5725436
[33]. Singh, A., Dua, R., Aggarwal, S., & Gill, S. Mast cell: a review. Teerthanker Mahaveer Univ J Dent, 2015;2:23-25.
[34]. Atiakshin, D., Samoilova, V., Buchwalow, I., Boecker, W., & Tiemann, M. Characterization of mast cell populations using different methods for their identification. Histochemistry and Cell Biology, 2017;147(6):683-694.
https://doi.org/10.1007/s00418-017-1547-7
PMid:28243739
[35]. Buckley, M., & Walls, A. F. Identification of mast cells and mast cell subpopulations. Allergy methods and protocols, 2008;285-297.
https://doi.org/10.1007/978-1-59745-366-0_24
PMid:18612617
[36]. Ribatti D et al. Mast cells in human placenta. Int J Dev Biol, 2022;66(1-2):59-66.
[37]. Skibinski G et al. Morphological plasticity of human placental mast cells. Histol Histopathol, 2007;22(4):417-426.
[38]. Tchougounova E et al. Evidence for a role of mast cells in the regulation of vascular permeability during placental development. Placenta, 2005;26(3):211-217.
[39]. Woidacki K et al. Mast cells: modulators of human placental development and function. Placenta, 2013;34(7):540-545.
[40]. Sierra A, et al. Distribution and degranulation patterns of mast cells in the human placenta and fetal membranes. Placenta. 2020;97:41-49.
[41]. Fedorova, E. A., Grigorev, I. P., Syrtzova, M. A., Sufieva, D. A., Novikova, A. D., & Korzhevskii, D. E. Detection of morphological signs of mast cell degranulation in the human choroid plexus using different staining methods. Morfologiia, 2018;153(2):70-75.
